Molded skins produced from a plurality of plastic materials having improved properties during airbag deployment at low temperatures

Abstract

The invention relates to a method and a device for the production of plastic molded skins, which are formed by consecutively performing a plurality of partial melting processes of a plurality of plastic materials, wherein the first plastic material is applied to the mold as a plastic powder in a centrifugal molding method and the second plastic material by a spraying method.

1 . A molded plastics skin for motor-vehicle-interior parts, e.g. dashboards and door cladding, produced by a process where the molded plastics skins are constructed by successive repeated continuous fusion of a plurality of plastics materials of different properties at surface regions of a heated mold,
 wherein   a) first, the first plastics material in the form of plastics powder is applied by a rotational sintering process (rotation of a powder box) to the mold, and the mold is heated to, and kept at, a first temperature of from 180 to 240 degrees C. during the fusion and gelling of the plastics powder, and so the first plastics powder applied adheres by fusion to the mold,   b) then a second plastics material is applied by a spray process, and the second plastics material here adheres by fusion to the first plastics powder, and then the mold is adjusted to a second temperature in such a way that the plastics material applied by spraying is heated to, and kept at, a temperature of 60 to 250 degrees C., and the first plastics powder and the second plastics material here react to completion and fuse to give a homogeneous molded plastics skin, and   c) the resultant molded plastics skin is cooled, and so it can be removed from the mold, and   the layer thickness applied of the first plastics powder applied to the mold is from 200 to 15 000 μm, and the layer thickness applied of the second plastics material applied is from 50 to 1700 μm; and   wherein the second plastics material is applied to the reverse side of the first layer in regions which have been isolated with the aid of fillets from the remaining regions of the reverse side; and   wherein an outer layer which is external within the plastics skin and has been applied by rotational sintering processes to the mold is composed of polyvinyl chloride, and a backing layer situated thereunder within the plastics skin, and applied by spraying to the mold is composed of a polyurethane.   
     
     
         2 . The molded plastics skin as claimed in  claim 1 , wherein a lower layer is composed of material having low-temperature flexibility. 
     
     
         3 . The molded plastics skin as claimed in  claim 2 , wherein the lower layer is composed of acrylates. 
     
     
         4 . The molded plastics skin as claimed in  claim 2 , wherein the lower layer is composed of unsaturated polyolefins. 
     
     
         5 . The molded plastics skin as claimed in  claim 2 , wherein the lower layer is composed of polyurethane. 
     
     
         6 . A molded plastics skin for motor-vehicle-interior parts, e.g. dashboards and door cladding, produced by a process where the molded plastics skins are constructed by successive repeated continuous fusion of a plurality of plastics materials of different properties at surface regions of a heated mold,
 wherein   a) first, the first plastics material in the form of plastics powder is applied by a rotational sintering process (rotation of a powder box) to the mold, and the mold is heated to, and kept at, a first temperature of from 180 to 240 degrees C. during the fusion and gelling of the plastics powder, and so the first plastics powder applied adheres by fusion to the mold,   b) then a second plastics material is applied by a spray process, and the second plastics material here adheres by fusion to the first plastics powder, and then the mold is adjusted to a second temperature in such a way that the plastics material applied by spraying is heated to, and kept at, a temperature of 60 to 250 degrees C., and the first plastics powder and the second plastics material here react to completion and fuse to give a homogeneous molded plastics skin, and   c) the resultant molded plastics skin is cooled, and so it can be removed from the mold, and   the layer thickness applied of the first plastics powder applied to the mold is from 200 to 15 000 μm, and the layer thickness applied of the second plastics material applied is from 50 to 1700 μm; and   wherein during the application of the second plastics material to the reverse side of the first layer, the regions not to be coated with the second plastics material have been covered with the aid of masks or covering elements; and   wherein an outer layer which is external within the plastics skin and has been applied by rotational sintering processes to the mold is composed of polyvinyl chloride, and a backing layer situated thereunder within the plastics skin, and applied by spraying to the mold is composed of a polyurethane.